“This country faces more serious problems today than at any time since the Great Depression,” Sanders told a crowd of 5,000 at Waterfront Park. “If you include the planetary crisis of climate change, it may well be that the challenges we face now are more dire than any time in our modern history.”

Sanders, 73, vowed to elevate issues like income inequality, climate change and campaign finance in the presidential campaign. He said that the “grotesque” level of money and power that the nation’s billionaires currently enjoy is “immoral, bad economics and unsustainable.”

While Sanders was praised by a string of onstage supporters, including environmental activist Bill McKibben, several leading Vermont Democrats, including Sen. Patrick Leahy, Gov. Peter Shumlin and former Gov. Howard Dean, were notably absent from the event. All three have thrown their support behind Hillary Clinton’s campaign.
While Clinton is by far the front-runner for the Democratic presidential nomination, Sanders, a self-described “democratic socialist,” believes he can fire up grassroots support among left-leaning Democrats who are unimpressed with Clinton.

The same anti-Clinton group had hoped for months that Massachusetts Sen. Elizabeth Warren would jump into the race. However, with Warren stating she will remain in the Senate and won’t seek the nomination, Sanders is well-positioned to draw support from the party’s progressive wing. His platform is in line with Warren’s agenda to rein in Wall Street banks, create a government-financed infrastructure jobs program and address the staggering college debt problem.

In his speech, Sanders hit all the right notes for progressives. He said the economic system is “rigged” against the middle-class and promised to help level the playing field by raising taxes on the rich and fighting against trade agreements that ship jobs overseas.

Sanders said he would build upon President Barack Obama’s Affordable Care Act by pushing for a single-payer health care system. He also promised to expand Social Security benefits, address climate change and push for the public financing of elections.

Sanders also noted that, unlike Clinton, he voted against the 2003 invasion of Iraq. However, he said he supported the U.S. working with an international coalition to bring down the Islamic State group.

Overall, Sanders painted himself as a candidate who plans to run a serious campaign on serious issues.

“This campaign is not about Bernie Sanders,” he told the crowd. “It is not about Hillary Clinton. It is not about Jeb Bush or anyone else. This campaign is about the needs of the American people, and the ideas and proposals that effectively address those needs. As someone who has never run a negative political ad in his life, my campaign will be driven by issues and serious debate.”